The present invention relates generally to irrigation equipment. More particularly, the invention disclosed herein relates to a programmable irrigation controller for multiple watering zones.
Vegetation typically grows in soil that has been watered by rain. However, normal and healthy growth of vegetation can be retarded and even prevented when natural rainfall fails to meet the requirements of that vegetation. Advantageously, artificial irrigation can compensate for the deficiencies of nature by supplying sufficient amounts of water directly to vegetation at predetermined intervals for predetermined lengths of time.
Early techniques for supplementing natural rainfall relative to vegetation located remote distances from a water source often comprised such rudimentary methods as a manual pouring of water directly onto vegetation by hand and bucket. Eventually, aqueduct systems simplified the task. A basic aqueduct systems typically comprises long furrows or pipes designed to transport water from a remote source, usually employing gravity, to an area immediately adjacent the vegetation sought to be watered. Eventually, diligent invention led to additional advances in irrigation. Animal power and mechanical lifting provided irrigation systems that were more efficient and less taxing on those who employed them.
Advances in generalized technology eventually led to still further improvements in irrigation. Steam power, the internal combustion engine, and electricity allowed irrigation systems to become fully mechanized. Previously state-of-the-art irrigation controllers gave way to mechanical devices with internal, often programmable, timers. These systems provided a means for automating the control of water flow from a pressurized water source through piping assemblies and the like to plural watering stations or zones.
Automatic electromechanical controllers for such systems typically incorporated conventional motor-driven electric clocks for allowing a user to program individual start times for particular irrigation cycles and watering stations. Calendar programs could provide the ability to select particular days for watering over a span of 14 days and more. With these electromechanical controllers, calendar programs would be operable by means of a disc that is rotated each 24 hours to a next-day position by a motor-driven clock. Unfortunately, such systems quickly become undesirably complex with increased numbers of watering zones, such as is required with golf courses, cemeteries, parks, and the like.
Again, innovation provided an incremental improvement with the development of solid state irrigation controllers thereby replacing the electric motors, mechanical switches, actuating pins, cams, levers, gears, and other mechanical devices with solid state electronic circuitry. With this, the systems allow programming of multiple start times and day programs for individual watering stations or zones, repeat cycles, and watering time selections in minutes or even secondsxe2x80x94all with increased accuracy coupled with a concomitant elimination of the complex interrelation of mechanical parts.
Generally, prior art solid state irrigation controllers incorporate a programmable microprocessor with a user interface that enables a programming of several watering stations or zones based on a plurality of timing variables such as daily, weekly, odd days, even days, start times, watering lengths, and still further variables. Each watering zone typically includes one or more sprinklers and a solenoid valve that is normally regulated by the microprocessor. The solenoid valves control the flow of water from a pressurized water source to a given watering zone. Certain systems visually communicate the current status of the system""s programmable variables by use of such means as liquid crystal displays (hereinafter xe2x80x9cLCDxe2x80x9d). Some systems allow a user to override the preprogrammed automatic watering operations by manual intervention. This allows the system to account for unusual circumstances such as excessive rain or drought.
It will be immediately apparent that this lengthy evolution of irrigation systems has resulted in state-of-the-art systems that are exponentially more efficient, convenient, and effective than their predecessors. Unfortunately, however, as with nearly all things, even advanced systems remain imperfect.
For example, although known prior art irrigation controllers have enabled remote communication between a remote unit and a controller microprocessor, this communication has been decidedly one sided. Irrigation controllers have allowed for the remote operation of water valves and the like by a sending of information from the remote unit to the microprocessor. However, they have not allowed an opposite stream of communicationxe2x80x94communication from the microprocessor to the remote unit. Accordingly, a remote user can not determine whether one or more watering zones is faulty (e.g., is in an open-circuit or closed circuit condition). Consequently, remote troubleshooting often becomes unduly burdensome.
Another shortcoming exhibited by prior art irrigation controllers is that they give a user insufficient flexibility. Although a user can select from multiple watering programs in prior art control systems, such systems do not allow a ready switching from one mode that employs one entire set of programs that the user has entered to a second or third mode that employs other sets of programs that the user has entered. Consequently, causing the irrigation controller to accommodate changes in seasons or the demands of germinating seeds are laborious tasks each and every time they must be accomplished.
Another shortcoming from which prior art irrigation controllers suffer relates to their current sensing circuitry, which is typically capable of sensing faulty valves within the irrigation system. Although such current sensing circuitry is useful for protecting an irrigation controller from harm from a faulty (i.e., shorted) valve, it is not capable of specifying how many valves are open in any given watering zone, which would allow the irrigation controller to adjust the maximum allowable current in the system. Furthermore, such systems are not able to determine when no valve is operational whereby the system may pump water with no valve open thereby causing damage to the pump and, possibly, other portions of the irrigation system.
A further deficiency in prior art irrigation controllers is that crucial information often is lost during extended periods when the overall system is without power, such as during winter months or extended periods of power failure. As a result, systems that lose their memory often will not recall whether they were on or off when they were last in use. When such a system again receives power, it may malfunction such as by activating water valves even while the system is down. Furthermore, such a system could lose all of the watering programs that had previously been entered such that a user would have to reenter each program sought to be employed.
Yet another drawback exhibited by irrigation controllers of the prior art is a common inability to provide a specialized mode that allows a user to activate multiple watering zones simultaneously. In day-to-day operation, this is a desirable restriction because having too many valves open during regular operation can cause malfunctions in the system such as from excessive loss in head. However, such an ability is highly desirable during such operations as winterizing procedures where a user seeks to blow the water from each of the zones to prevent damage from freezing water. As a result, with present-day irrigation controllers the user must activate each zone separately in an arduous and time-consuming procedure.
Finally, a most prevalent shortcoming exhibited by prior art irrigation controllers is that programming them is often a difficult and confusing task. For example, a user seeking to program a multiplicity of watering zones often is unable to determine which watering zone is presently selected for programming. Furthermore, other than by his or her own memory, users typically have no means of knowing which function of the irrigation controller he or she is programming. As a result, users typically are forced to program an irrigation controller blind whereby the programming procedure often proves arduous and frustrating.
Accordingly, it is clear that it would be advantageous if the evolution of irrigation controllers were to continue with an invention that could provide a solution to one or more of the deficiencies left by the prior art. However, it is still clearer than an irrigation controller presenting a solution to each and every one of the aforementioned deficiencies in the prior art while providing a number of heretofore-unrealized advantages would comprise a marked advance in the art.
Advantageously, the present invention sets about with the broadly-stated goal of providing an irrigation controller that meets each of the aforementioned needs that have been left unmet by the prior art and thereby presents a further step in the evolution of irrigation in general.
Stated more particularly, a principal object of the present invention is to provide an irrigation controller that is capable of sending diagnostic information and the like from a main irrigation control unit to a remote unit that can be retained by a user in the field to provide for efficient system diagnosis and repair.
A further object of the invention is to provide an irrigation controller that allows flexible shifting between a plurality of watering modes including specialized modes for germinating seeds and the like.
The invention has the still further object of providing an irrigation controller that does not lose memory even during extended periods without power. A resultant object is to provide an irrigation system that remembers whether it was on or off when it was last powered and that remembers irrigation programs that have been stored in its memory.
An additional object of the invention is to provide an irrigation controller that provides a specialized mode, which may be termed a winterize mode, wherein a user can manually activate a multiplicity of watering zones simultaneously whereby winterizing procedures can be carried out more efficiently and conveniently.
The invention also seeks to provide an irrigation controller that incorporates current sensing circuitry that can detect how many valves are operational in each watering zone to allow the irrigation controller to adjust the maximum allowable current in the system and can prevent damage to the irrigation system by detecting when no valve is operational.
A still further object of the invention is to provide an irrigation controller that guides a user through the programming process by providing an indication of presently selected altering zones and, possibly, programming functions.
In accomplishing the aforementioned and still further objects and advantages, a most basic embodiment of the irrigation controller includes a means for enabling an inputting of commands relating to watering programs, a means for processing commands relating to watering programs, a means for controlling a plurality of watering zones according to the commands, a means for retaining information relating to watering programs, and a means for displaying information relating to watering programs. In this embodiment, the means for enabling an inputting of commands, the means for receiving and processing commands and controlling a plurality of watering zones, and the means for retaining information in combination may be termed a means for allowing a user to establish watering programs.
Preferably, the means for allowing a user to establish watering programs will enable a programming of a selected start time and a selected watering length individually for each of the watering zones while further allowing a programming of a single selected start time and a single selected watering length for a plurality of watering zones. The means for processing commands relating to watering programs and the means for controlling the plurality of watering zones according to the commands may comprise a microprocessor.
The irrigation controller may be improved further by enabling a programming of a Skip Day command wherein the watering program skips one or more days, a Water Percent command wherein the watering program waters for a selected percentage of the selected watering length, and, additionally or alternatively, a Germinate command wherein a germinate watering program temporarily replaces a basic watering program.
Ideally, the irrigation controller will include a means for preventing simultaneous operation of a number of valves excessive of the maximum number of valves that allows for proper operation of the irrigation system during a normal operation of the irrigation controller. This means may comprise a power supply with a maximum current capability, a means for measuring current draw from the power supply, which may comprise an analog-to-digital converter, and a means for comparing the current draw from the power supply with the maximum current capability of the power supply.
Furthermore, a preferred means for allowing a user to establish watering programs will further enable an inputting of a Winterize command wherein a multiplicity of valves can be operated simultaneously. Further advantage may be had by providing a Review command that causes the irrigation controller to enter a review mode wherein the means for enabling an inputting of commands relating to watering programs is disabled whereby a user can review a given watering program without risk of accidentally altering the watering program.
Preferred embodiments of the irrigation controller will further include a means for retaining information relating to watering programs in the absence of power. With this, the irrigation controller can retain watering programs and an indication as to whether the irrigation controller was last on or off even during extended periods without power. This means may comprise an electrically erasable programmable read-only memory device (EEPROM) operably associated with the microprocessor. Ideally, the EEPROM will include sufficient read-only memory for simultaneously retaining a plurality of watering programs that can be selectively accessed.
A further refinement of the invention may be in the form of a means for detecting how many valves are operational in a given watering zone, which may comprise an analog precision rectifier, and a means for automatically adjusting a maximum allowable current in response thereto.
Yet another improvement to the irrigation controller may comprise a remote control unit in cooperation with a means for transmitting diagnostic information to the remote control unit regarding a status of the valves of the irrigation system. Preferably, such an irrigation controller would be further supplemented by a means for inducing remote operation of the valves of the irrigation system. The means for transmitting diagnostic information to the remote control unit ideally will comprise a means for sending a signal from the remote control unit to the microprocessor to induce the microprocessor to send a test signal to each valve in the irrigation system, a means for measuring a current across each valve, a means for determining based on the current across the valve whether each valve is open or shorted, a means for transmitting whether each valve is open or shorted to the remote control unit, and a means for displaying the status of the valves in the irrigation system on the remote control unit. The means for displaying the status of the valves on the remote control unit may comprise at least one LED numeric display in combination with a bi-color status LED. With this, the LED numeric display can display the number or numbers of any faulty zones, and the bi-color status LED can indicate with a first color whether the faulty zone is open and with a second color whether the faulty zone is shorted. The means for transmitting diagnostic information to the remote control unit may be founded on a communication port comprising a four wire interface with two wires sending power and ground and two wires providing a differential signal path.
To simplify programming of the irrigation controller and to eliminate blind programming, the preferred irrigation controller includes a means for selecting one or more of the plurality of watering zones to create a selected watering zone or zones in combination with a means for indicating the selected watering zone or zones. The means for selecting one or more of the plurality of watering zones may comprise a plurality of keys, such as membrane keypad keys. The means for indicating the selected watering zone or zones may comprise an indicator mechanism, such as an indicator light that may be an LED, disposed proximate to each key for indicating whether the watering zone that is selectable by that key is a selected watering zone. The means for indicating selected watering zones may be supplemented by a means for indicating an active programming function, such as the Start Time and Watering Length functions.
Of course, one should remain mindful that the foregoing discussion is designed merely to outline broadly the more important features of the invention to enable a better understanding of the detailed description that follows and to instill a better appreciation of the inventor""s contribution to the art. Before an embodiment of the invention is explained in detail, it must be made clear that the following details of construction, descriptions of geometry, and illustrations of inventive concepts are mere examples of possible manifestations of the invention.